Subject: [PATCH v4 3/3] gnu: bootloader: Add a friendly error message of menu-entry.

From: [email-masked]
Date: Mon, 5 Sep 2022 01:25:42 +0800

From: tiantian <[email-masked]>

* gnu/bootloader.scm (report-menu-entry-error): New procedure.
(menu-entry->sexp): Add a call to `report-menu-entry-error'.

Co-Authored-By: Julien Lepiller <[email-masked]>
---
v3:
The error message like so:

guix system: error: invalid menu-entry: #<<menu-entry> label: "test" device: #<file-system-label "guix-root"> device-mount-point: #f linux: #f linux-arguments: () initrd: #f multiboot-kernel: #f multiboot-arguments: () multiboot-modules: () chain-loader: #f>
hint: Please chose only one of:

  1. direct boot by specifying fields `linux', `linux-arguments' and `linux-modules',

  2. multiboot by specifying fields `multiboot-kernel', `multiboot-arguments' and `multiboot-modules',

  3. chain-loader by specifying field `chain-loader'.

The code of `report-menu-entry-error' is quoted from Julien Lepiller.
Thanks the help from Julien Lepiller.

v4:
The checks of the lists are cancelled and the check of initrd is moved
to the first patch.

 gnu/bootloader.scm | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/gnu/bootloader.scm b/gnu/bootloader.scm
index 9fe6b65212..da65b9d5d5 100644
--- a/gnu/bootloader.scm
+++ b/gnu/bootloader.scm
@@ -34,6 +34,8 @@ (define-module (gnu bootloader)
   #:use-module (guix diagnostics)
   #:use-module (guix i18n)
   #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-34)
+  #:use-module (srfi srfi-35)
   #:use-module (ice-9 match)
   #:export (menu-entry
             menu-entry?
@@ -110,6 +112,23 @@ (define-record-type* <menu-entry>
   (chain-loader     menu-entry-chain-loader
                     (default #f)))         ; string, path of efi file
 
+(define (report-menu-entry-error menu-entry)
+  (raise
+   (condition
+    (&message
+     (message
+      (format #f (G_ "invalid menu-entry: ~a") menu-entry)))
+    (&fix-hint
+     (hint
+      (G_ "Please chose only one of:
+@enumerate
+@item direct boot by specifying fields @code{linux},
+@code{linux-arguments} and @code{linux-modules},
+@item multiboot by specifying fields @code{multiboot-kernel},
+@code{multiboot-arguments} and @code{multiboot-modules},
+@item chain-loader by specifying field @code{chain-loader}.
+@end enumerate"))))))
+
 (define (menu-entry->sexp entry)
   "Return ENTRY serialized as an sexp."
   (define (device->sexp device)
@@ -146,7 +165,8 @@ (define (menu-entry->sexp entry)
                   (label ,label)
                   (device ,(device->sexp device))
                   (device-mount-point ,mount-point)
-                  (chain-loader ,chain-loader)))))
+                  (chain-loader ,chain-loader)))
+    (_ (report-menu-entry-error entry))))
 
 (define (sexp->menu-entry sexp)
   "Turn SEXP, an sexp as returned by 'menu-entry->sexp', into a <menu-entry>
-- 
2.37.2